The invention as described herein is for attachment to a planter row unit to be used in minimum or no-till conditions. Over the past forty years there has been a migration in agriculture from full tillage prior to planting to no or minimum tilled planting. Full tillage operations may have included multiple passes and resulted in a soil surface having a relatively smooth, soft and uniform composition. The tilled seedbed offered a uniformly inviting environment for introduction of fertilizer. By contrast, the field and soil conditions offered by the typical no-till or minimum till environment are inhospitable. The surface cover and soil conditions are typically non-uniform. The field residue, although substantially decomposed, presents ample opportunities for plugging, wadding and or repelling of a disc, coulter or knife inserted therein. Farmers face the challenges presented by adoption of no-till and minimum till practices now out of necessity versus choice as required by the ever competitive agricultural environment.
Since the introduction of the modern planter row unit, many changes have taken place within agriculture as a result of both internal and external forces. Genetic, chemical and fertilization technologies have increased yields while globalization has increased competition to produce more bushels at less cost. Another important force in the market has been consolidation of operations and growth of farming operations. Farming operations now may cover thousands and tens of thousands of acres, acreages not possible or thought plausible twenty to thirty years ago. This consolidation has fueled intense competition to reduce operating costs and maximize equipment utilization rates to increase profitability. As a result operators are pulling larger row crop planters, driving faster across the field during planting and reducing the trips to and across the field. The drive to reduce the trips across the field has spurned interest in both low and no-tillage planting operations. These practices are also sought because fewer passes over a field require less input cost. Additionally, due to reduced margins and larger equipment, fewer farmers are farming more acres of ground. This has produced the impetus to increase planting speed up to 6-7 miles per hour.
Environmental laws and regulations passed since the initial introduction of the modern planter row unit governing water run-off and soil erosion require implementation of low-till or minimum till practices. Further operational changes are also driven by the impact of government price supports and payments. Compliance with environmental laws and regulations is required for enrollment in most government programs and payments may be contingent on compliance with modern soil conservation techniques.
What has not changed, however, is the length of the seasons and the importance of field conditions to the resultant crop planted. Per region, there are typically only so many days best suited for planting crops. Furthermore, planting in sub-optimum conditions still increases the potential for a poor result and reduced crop yields. Now then, more than ever, farm operators have an incentive to reduce costs and comply with the standards of government programs through adoption of one-pass or one-trip technologies. Minimal disruption of the soil is preferred for both compliance reasons and economics i.e. one-trip planting requires less fuel and labor expense. These factors have changed the environment and requirements for the modem planter row unit. The field and market environment today therefore, requires planter attachments that can handle increased variations in the soil and field conditions.
A compliment to one-pass planting methods is the introduction of fertilizer at the time of planting. This practice is supported by agricultural research indicating a small amount of fertilizer concurrent with the introduction of seed and in relative proximity to the seed, provides the emerging plant with a boost or jumpstart. Although either liquid or dry fertilizer can be used to provide this “jumpstart”, many users have migrated to liquid because it absorbs into the soil better and is easier to handle. Directed placement of fertilizer (also known as “starter” or “jumpstarter” fertilizer) in close spatial relationship to seed at the time of planting is therefore beneficial to the plant. The benefits of this practice are supported by ample trials and evidence suggesting improved plant growth characteristics and ultimately improved yields. To achieve the desired benefits of starter fertilizer requires attainment of the following objectives:    1. Proper fertilizer placement in the soil;    2. Proper fertilizer placement in relation to the seed as the seed is placed in the soil; and,    3. Segregation of the seed and fertilizer as placed in the soil.
The resulting detrimental effects of not achieving the above objectives are understood by those practiced in the arts. Placing the fertilizer on top of the soil reduces the value of the fertilizer to the seed and exposes the fertilizer to wind or water erosion. Placing the fertilizer too far from the seed, either vertically or horizontally, reduces the seed's access to the fertilizer, thereby reducing the effectiveness of the fertilizer. It is also advantageous to minimize the contact of the liquid fertilizer with the planting equipment. Liquid fertilizer is known to degrade both paint and metal surfaces potentially decreasing equipment operational run times. The corrosive nature of the liquid fertilizer also increases operator difficulties in working on equipment exposed to said fertilizer. Direct placement of corrosive liquid fertilizer upon the seed can degrade and or destroy the planted seed.
The prior art, however, has failed to enable an apparatus or method of starter fertilizer placement which accomplishes the above objectives. A review and examination of the prior art highlights the weaknesses of the prior art to enable liquid fertilizer delivery in close proximity to a seed trench. As result, the solutions available in the prior art are inadequate.
Prior Art Review
U.S. Pat. Nos. 6,912,963 and 6,644,224 issued to Bassett both disclose single disc fertilizer opener mounted to a row unit. Both patents fail to teach a method or apparatus for directed placement of liquid fertilizer and incorporated within the soil therein. Furthermore, Bassett is silent on the necessity of maintaining soil between the placed fertilizer and seed. U.S. Pat. No. 6,347,594 issued to Wendling teaches a single disc seed opener in combination with a closing wheel. To respond to changes in soil elevation and conditions, Wendling requires mounting the assembly on the planter frame and for the disc opener to be spring loaded. Furthermore, angle of the disc blade is to be angled at approximately five (5) degrees from the direction of travel. As deployed, under Wendling, all units are mounted at the same angle to the direction of travel. This mounting method results in high side loading forces at the point of attachment for each unit. Placement of fertilizer using the seed tube as taught by Wendling would result in splashing fertilizer on the disc and potentially the seed. U.S. Pat. No. 4,760,806 issued to Bigbee teaches another frame mounted single disc in combination with a seed tube. See also U.S. Pat. No. 5,640,914 issued to Rawson; U.S. Pat. No. 5,626,196 issued to Hughes; and U.S. Pat. No. 4,987,841 issued to Rawson provide other examples of frame mounted single disc openers. U.S. Pat. No. 5,787,994 issued to Frieson discloses a single disc opener mounted to the parallel linkage of a row unit. The angle of the single disc as taught by Frieson is four degrees from the planter direction of travel; the fertilizer placement tube as mounted moves in the same direction as the planter direction of travel. The disc is coultered or tined as taught by Friesen and the fertilizer feed tube is mounted to an upright mounted groove forming shank. A spring is disclosed to bias the shank against the disc having a coulter or tine. No mechanism is disclosed to bias the shank against the furrow to hold the shank in the furrow. No mechanism is disclosed to move the fertilizer feed tube discharge outlet in combination with the opener assembly. Finally, U.S. Pat. Nos. 6,260,632 and 6,024,179 issued to Bourgault discloses a floating disc opener contacting an inner side of the disc blade. As disclosed the assembly does not extend to or past the outer perimeter of the disc. The fertilizer tube as taught by Bourgault does not extend into the furrow created by the disc.
The above prior art alone or in combination fails to teach a planter row unit mounted attachment for directed delivery and incorporation of liquid fertilizer in no or minimum till conditions which is compact and light in weight. The prior art fails to teach an apparatus that minimizes interference with seed placement while minimizing soil disruption for placement of said fertilizer. The prior art fails to teach a liquid fertilizer opener that creates minimal side loading using a symmetrical but opposite mounting structure.
As disclosed and claimed, the discs are angled and work in combination with a furrow control strap which is mounted to the outer edge of the disc. As configured, the furrow control strap always faces to the outside of the planter row units. For example, when mounted on the left side planter row units, the furrow control strap will be on the left side of the assembly with the fertilizer feed shoe on the right. Conversely, on the right hand side planter row units, the furrow control strap will be on the right side of the assembly with the fertilizer feed shoe on the left.
The outer edge of the single disc blade is flat and the inner portion is beveled. The beveled edge of the disc cuts the furrow for insertion of the spring loaded fertilizer feed tube shoe within the furrow. The spring loaded fertilizer feed tube shoe is pre-loaded during assembly so that the fertilizer feed tube shoe is biased both to the bottom of the furrow and against the interior of the disc. The lower front portion of the fertilizer feed tube shoe rests against the lower aft portion of the fertilizer feed tube pocket. This allows the fertilizer feed tube shoe to maintain its substantially horizontal orientation but pivot upward in the event of an over load condition i.e. contact with a stone or clod, thereby preventing catastrophic failure. The upper portion of the fertilizer feed tube pocket serves to strengthen the disc hub support beam against side loading forces. The fertilizer feed tube protective pocket also reduces contact between the fertilizer feed tube